Related wiseGEEK articles What Is the Excretory System? What Is Calcium Homeostasis? What Is Negative Feedback in Homeostasis? What Are the Different Types of Homeostatic Control Mechanisms? What Is Glucose Homeostasis? What is Osmoregulation? What Is Oncotic Pressure?
CategoryAnatomy and Physiology
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This Day in History ,?:??more... get widget var wGFWidget = {}; var loadHistoryWidget = function() { var aDom = {_sScriptConatinerId: "PageArticle_history-widget-ScriptContainer_id", _sWidgetTextBlock: "PageArticle_history-widget-FeedText_id", _sWidgetYearBlock: "PageArticle_history-widget-FeedYear_id", _sWidgetDateBlock: "PageArticle_history-widget-FeedDate_id", _sWidgetMoreLink: "PageArticle_history-widget-FeedLink_id" } initHistoryWidget(aDom); } if(window.addEventListener) { window.addEventListener('load', loadHistoryWidget, false); } else if (window.attachEvent) { window.attachEvent("onload", loadHistoryWidget); } @media screen and (-webkit-min-device-pixel-ratio:0) { .RightADSBorder { background-color: #999999; } } ? ? ?Homeostasis is a point of balance or internal equilibrium. All living organisms strive for homeostasis, using a variety of techniques which range from the release of hormones to physical reactions like sweating or panting. In a simple example of homeostasis, the human body uses several processes to regulate its temperature, trying to stay within an optimal range for healthy functioning. Spikes or declines in body temperature reflect an inability to maintain homeostasis, and a corresponding problem.
One way to think about homeostasis is to imagine a set of scales. If coins are poured into one side of the scale, the scales slip out of balance. If weights are piled onto the other side, the scales will eventually balance. If too many weights are added, the scales will become unbalanced again. The body is like a set of scales, working constantly to achieve a state of balance. Unlike scales, the body is extremely complex, requiring numerous tiny adjustments every second, and new input is constantly putting the body off-balance.
There is one process in homeostasis known as negative feedback. Negative feedback reflects the body's desire to return to a normal state, signaling that a problem is occurring and regulating the resulting processes to ensure that the body reaches homeostasis rather than going too far in the wrong direction. In positive feedback, the body encourages the rapid increase of an activity to deal with an emerging situation, as for example when white blood cell production increases to cope with an infection.
A number of things can interfere with the body's desire to achieve homeostasis, causing a variety of medical conditions. Hormone imbalances, infections, dehydration, gout, and hypoglycemia are all examples of conditions which are related to homeostasis. Homeostasis can also be disrupted by introducing toxins into the bloodstream, including toxins which are meant to have a medical benefit, such as chemotherapy. Blood pressure, temperature, blood sugar, hormone levels, and enzyme levels are all homeostatic processes in the human body, and problems with any of these processes can indicate the presence of an underlying medical condition.
People are generally healthier when their bodies are in a state of homeostasis, and their bodies send numerous messages to promote homeostasis. For example, when low blood sugar appears to be developing, people tend to feel hungry, because their brains tell them to eat. Specific cravings can emerge in response to nutritional deficiencies, with the brain essentially creating a shopping list which will help the body reach a state of balance. People may also feel driven to drink water, exercise, or engage in other activities.
Discuss this Article var adp_post_blocks = [];var adp_posts_container_node_id = "PageArticle_discussionPosts-postsContainer_id"; adp_post_blocks.push("post_94944"); 3Homeostasis is also related to aging and illness. Since the body becomes less efficient at maintaining homeostasis as it ages and begins to break down, people become more susceptible to disease.It really is a very complex system, and one area going out of proportion can really throw a lot of things off.
For instance, if your blood sugar gets thrown off, you can get caught up in a rollercoaster of too high/too low blood sugar, which can cause weight gain, high blood pressure, and also increases the amount of free radicals in your body, which accelerates aging. - naturesgurl3 adp_post_blocks.push("post_94942"); 2Homeostasis mechanisms also plays a large role in the body during exercise.
For example, since the body gets hotter during exercise, you start to sweat to bring the body back down to a suitable temperature.
Also, a lot of mechanisms kick in to keep enough oxygen flowing around the body -- the digestive system slows down to provide more oxygen to the parts of the body that are working harder, and the urge to breathe deeper also gets more oxygen into your system and expels the carbon dioxide, all of which help to keep the body in a homeostatic state. - rallenwriter (function(){ var addEvent = function(obj,event,hnd){ if (obj.attachEvent) obj.attachEvent('on' + event,hnd); else if (obj.addEventListener) obj.addEventListener(event,hnd,true); }, removeEvent = function(obj,event,hnd){ if (obj.detachEvent) obj.detachEvent('on' + event,hnd); else if (obj.removeEventListener) obj.removeEventListener(event,hnd,true); }, onCoreScriptsLoad = function(){ removeEvent(document.getElementById("PageArticle-loadDiscussionPostBoxButton_id"),'click',onLoadDiscClick); PageArticle.getInstance().load(); PageArticle.getInstance().showDiscussionPostBox(); }, onLoadDiscClick = function(){ loadCoreScripts(onCoreScriptsLoad); return false; }, t = false, onWindowLoad = function(){ if (!t){ t = true; addEvent(document.getElementById("PageArticle-loadDiscussionPostBoxButton_id"), 'click', onLoadDiscClick); } }; addEvent(window,'load',onWindowLoad);})(); ▼ Post your comments Written by S.E. Smith
Edited by O. Wallace
Last Modified: 16 December 2010
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